Code Division Multiple Access (CDMA) Direct Sequence Spread Spectrum Signaling is one of the most promising multiplexing technologies for cellular telecommunications services. The advantages include superior performance in multipath environments and improved cellular capacity. In spite of a multitude of advantages this technology offers, conventional CDMA systems have very limited user throughput and are not well suited to. "bandwidth on demand" multimedia applications. To accommodate such greater bandwidth applications, a Multi-Code CDMA (MC-CDMA) system was proposed and is the subject of U.S. Pat. No. 5,442,625, entitled "Code Division Multiple Access System Providing Variable Data Rate Access To A User," issued on Aug. 15, 1995. A straightforward implementation of a receiver for the MC-CDMA system may be significantly more complex than a receiver for a conventional CDMA system. Care must be taken to avoid increasing the complexity of the receiver by a factor of N in order to support N channels.
The patent applications "METHOD AND APPARATUS OF A MULTI-CODE CODE DIVISION MULTIPLE ACCESS RECEIVER HAVING SHARED ACCUMULATOR CIRCUITS" by H. C. Huang, C.-L. I, A. Partyka, S. ten Brink and C. A. Webb III, Ser. No. 08/700,257, filed on Aug. 20, 1996; "METHOD AND APPARATUS OF A MULTI-CODE CODE DIVISION MULTIPLE ACCESS RECEIVER USING A SINGLE DATA CORRELATOR" by H. C. Huang, C.-L. I., S. ten Brink and C. A. Webb III, Serial No. 08/700,262 filed on Aug. 20, 1996, and "AN IMPROVED MULTI-CODE CODE DIVISION MULTIPLE ACCESS RECEIVER," by C.-L. I., A. Partyka, and C. A. Webb III, now U.S. Pat. No. 5,737,326 issued on Apr. 7, 1998, describe various techniques for reducing the circuitry and the resulting associated cost and power consumption of MC-CDMA receivers.
Notwithstanding the improvements provided in those applications, there is a continuing need to further reduce the cost and power consumption at both the transmitter and receiver locations. Increases in cost and power consumption are of particular concern for mobile terminals.